GMC Complaints

Transmission Shuttering which was confirmed from from GMC dealership , but refused to do any repairs after confirmation or diagnostic and test driving. Demanded a 220$ fee be paid before releasing my vehicle back. Also gave GMC Bulliten # 25-NA-148 which states the same issues I'm currently having.

Driving down the road and engine shut off and would not start back. Had it towed to dealer and it needed a motor replacement. Waited over a month for the shop to finish it. New motor has 3k miles on it and is making noise, transmission is stuttering hard and the air conditioning quit working all around the same time. Had to take the truck back to the dealer after the replacement motor was installed because of a faulty “new” starter.

[XXX] we bought our 2021GMC Sierra 1500 from Dealer with 39842 on it. we drove the truck 2910 miles when we checked the oil it was 2 quarts low at 42752. we added oil at that time and called our local dealer to make appointment . appointment at Bowser route 51 Pleasant Hills PA 15236 They informed us they would have to charge us for an oil change to start an oil consumption test on 10/23/25 miles 43829. 11/24/25 brought back to Dealer they said the oil was full yet i checked it in morning it was1/4 low. 1/7/26 brought back to dealer this time they let our truck sit over night the best way to check it and found it to be 3/4 low with only 1,698 miles driven also the antifreeze reservoir was low also they topped off both. 3/8/26 I Checked it ,its now 1 quart low with 1,097 miles driven milage on truck now is 46,623. Summarize GMC will not even look into why my truck is using oil not once my truck is still under warranty where is the consumer protection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Randomly when the truck is turned on, the turn signals will stop working, no noise, nothing. When this happens, the infotainment system also stops working. It is unsafe to be driving and not knowing if your signals are working or not. This has been happening since the truck was purchased from the dealer.

Another GM truck AFM failing. It failed at 70,000 miles causing P0307 cylinder 7 misfire. No aggressive driving just commuting to work. Truck just got done with a new oil change. It's another to add to the hundreds/thousands seen on Reddit threads of all 5.3/6.2 AFM/DFM that this organization turns a blind eye to.

Dear General Motors Customer Assistance Center, I am writing to formally file a complaint and request assistance regarding a serious mechanical failure with my 2018 GMC Acadia SLT. I purchased this vehicle when it had approximately 7,000 miles on it after it was transported from Florida. Since owning the vehicle, I have properly maintained it and had it serviced through Suttle Motors dealership in Newport News, Virginia. Recently, while driving on the highway to have tires installed, the vehicle suddenly stalled while I was in traffic. This caused a very dangerous situation, as traffic behind me was forced to abruptly slow down and I was nearly rear-ended due to the sudden loss of power. Because the vehicle was no longer drivable, I had it towed to Suttle Motors for inspection. After examining the vehicle, the service department informed me of the following issue: “The transmission solenoid valve is stuck and it has burnt the transmission fluid. The vehicle will require a full transmission replacement. The estimated cost is $7,769 with a 3-year/100,000-mile warranty.” I was extremely shocked and disappointed to receive this news. My vehicle currently has only 67,000 miles, and I have taken care to maintain it properly through the dealership. Experiencing a complete transmission failure at such relatively low mileage is very concerning, especially considering the dangerous situation it created on the highway. Given the circumstances, I am requesting that General Motors review this matter and advise whether any goodwill assistance, repair support, or coverage options may be available to help resolve this issue. I would greatly appreciate your prompt attention to this matter. I can provide service records and documentation from Suttle Motors if needed. Thank you for your time and consideration. I look forward to your response.

At 27, 000 miles while on vacation, over 1000 miles from home, the lifters and bearings grenaded the motor. The vehicle sat at the dealership for a month waiting for a motor replacement. This could have been much worse as we had just driven through mountains the day before. Had this happened in the mountains this could have been deadly. The engine was replaced, but we have no faith in the new engine as these are failing also. This is unacceptable for any vehicle, let alone an $85,000 Yukon. We have also had several issues with water leaking in from the sunroof also. Gm's solution to me basically missing 3 and a half days of a 7 day vacation was to give me enough gm points to get a free oil change. The dealership was great to deal with, the people I dealt with at GM were not very helpful at all.

The oil cooler line is leaking, and the vehicle is available for inspection upon request. This safety concern is addressed under GM Program N192220080. The Hazard is Present: The leak is active. The risk of total line detachment and engine seizure is the same in Texas as it is in Alaska (the US state the GMC recalled the exact same part). An engine seizure and loss of propulsion is an immediate danger to passengers within the effected vehicle, as well as the other vehicles on the road. The Admission of Defect: GM’s offer to provide the part (Part #85136335) confirms that my vehicle’s hardware is part of the failed batch. The vehicle was inspected by an authorized GMC dealership on 01/14/2026, confirming the leak and potential safety hazard with continued driving of the vehicle. The issue was submitted to the GM Customer Care team, Case #[XXX]. The only warning of the defective oil cooler line leak was oil on the ground underneath the vehicle after driving. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I was driving 55 miles an hour on an Expressway. And suddenly my truck just shut off.The brake became very hard unable to break very scary situation for me and my children. Engine power was reduced and would not start, many errors came up. The vacuum pump failed, which also caused the cam shafts to fail.The vacuum pump exploded into pieces and sent metal into my engine.

Coolant Leaking at 22K miles, smell of coolant, check engine light on and off 2X's. Coolant evidence on driveway and in engine cabin. Known condition for GM Model. No parts available for replacement. No recall for issue.